1. Field of the Invention
The present invention relates to an image forming apparatus such as an electrophotographic copying machine and a facsimile apparatus, and more particularly to an image forming apparatus which uses a neural network for controlling the automatic exposure mode in which the apparatus itself judges the condition of an original to be copied and then automatically controls various control items to form a copy image.
2. Description of the Related Art
An image forming apparatus such as an electrophotographic copying machine is conventionally so constructed as to preliminarily store various conditions of originals to be copied and various control items corresponding thereto in a data table, to read conditions of originals with use of an automatic exposure sensor when the automatic exposure mode is selected, and to read conditions of respective control items from the data table corresponding to the reading results by the automatic exposure sensor.
In order to realize the optimum copying condition fitting each original to be copied at performing automatic exposure copying, a conventional image forming apparatus like the one mentioned above requires a number of control items, for example, exposure magnitude, charging quantity, developing bias voltage and the like, which should be adjusted for each of various input conditions more accurately representing conditions of originals to be predetermined and individually controlled in a detailed manner. However, preliminarily storing a number of input conditions and all the output conditions for a plurality of control items concerning the input conditions in the form of a data table requires substantial memory area, and in addition, predetermining all conditions in detail requires substantial labor. Furthermore, it is, in fact, difficult to completely read and store conditions of all originals while carrying out automatic exposure copying.
Under these circumstances, exposure control using a neural network (neurocomputer) has been disclosed, for example, in Japanese Patent Application Laid-Open No. 2-96723 (1990), Japanese Patent Application Laid-Open No. 2-183238 (1990), and others. All of these however relate to the exposure control technique for cameras, in particular to the exposure control for taking a picture under backlight and are not applicable to an image forming apparatus. Furthermore, the present applicant in Japan has filed applications represented by Japanese Patent Application No. 2-112188 (1990) and others; these applications relate, however, to the color adjustment technique for color copying machines.